feat: set a continuation prompt for supporting shells (#3322)

* feat: set a continuation prompt for supporting shells (#3134)

* docs: fixed wording of documentation

* fix: continuation prompt is now only set once

* fix(docs): fixed typo in advanced-config/README.md

Co-authored-by: Segev Finer <segev208@gmail.com>

* fix: update --continuation argument

Co-authored-by: David Knaack <davidkna@users.noreply.github.com>

* fix: updated continuation prompt

- PROMPT2 was fixed to be set only once in zsh.
- `continuation_symbol` and `continuation_format` were removed in
  place of a single variable; `continuation_prompt`.
- The continuation prompt was moved out of the character module.

* fix: ran rustfmt

* docs: updated continuation prompt docs

Co-authored-by: Segev Finer <segev208@gmail.com>
Co-authored-by: David Knaack <davidkna@users.noreply.github.com>

src/configs/mod.rs

@@ -80,6 +80,7 @@ pub struct FullConfig<'a> {
     // Root config
     pub format: String,
     pub right_format: String,
+    pub continuation_prompt: String,
     pub scan_timeout: u64,
     pub command_timeout: u64,
     pub add_newline: bool,
@@ -158,6 +159,7 @@ impl<'a> Default for FullConfig<'a> {
         Self {
             format: "$all".to_string(),
             right_format: "".to_string(),
+            continuation_prompt: "[❯](bold yellow)".to_string(),
             scan_timeout: 30,
             command_timeout: 500,
             add_newline: true,